Facebook has issued invites for an event at its California headquarters next
week, stirring rumours that the social network is planning its own mobile
phone.

The invite for the event, which takes place in California next Tuesday, says "Come and see what we're building". While it's possible that Facebook is simply unveiling another update to its website, there have been frequent rumours that the company plans to make its own mobile phone.

Recent reports have suggested that the company is working on a Facebook handset with manufacturer HTC. The new device would connect directly to a user's Facebook account and run software such as Facebook Messenger and Instagram, the picture sharing service Facebook bought last year.

Though Facebook has stressed that it needs to improve its mobile offerings - the company makes less from advertising to mobile users than to those who interact with the site on a PC - the company has never suggested that it would make its own handset.

Mark Zuckerberg, Facebook's founder and chief executive, said last year: "Building out a phone wouldn't make sense for us to do."

Zuckerberg has talked in the past about the need to improve Facebook search, so there is some speculation that next week's event will be about that.